Pardon me for saying this, but asking if individual dating between two or more races is advisable is almost like a statement of racism, pardon me again for saying this. There's literally nothing wrong with interracial relationships, i mean, no race is better than the other in the manner of genes, behavior, character, spirituality, etc. It is only in our sentimental expressions we often think one should date persons belonging to their own race. And these wrong judgments are usually passive behaviors exhibited by the old, unenlightened, inexperienced, naive, and most especially, racist minds.
Come to think of it, this is actually a very good question. Am aware of certain people in my country who would rather their kids get married to their own race rather other races. Most of theses people are those types mentioned above. But thankfully, the world is gradually ridding itself of such people through education and other forms of enlightenment, as well as socialism.
My personal opinion is that, as long as interracial union do not any way possible affect our very existence in a negative way, then there's absolutely nothing wrong with it. It in fact aids better genes in terms of reproduction when two people of different race are married.